Finally built my variable DC load which I've named the LAMB (Large Array of Miniature Bulbs). Precious little sun here in the UK just now, but snatched a few moments today.
With the LAMB set to a high resistance, the panel has a high voltage but low current. When all the LAMBs bulbs are lit, its low resistance results in low panel voltage but high current. Neither of these result in maximum power.
With just the right number of bulbs lit, maximum power can be extracted from the solar panel.

By Julian

Youtuber, shed dweller, solar charge controller aficionado

9 thoughts on “Mppt solar charge controller #4 – finding maximum power with the lamb”
  1. Avataaar/Circle Created with python_avatars Pieter G says:

    LAMB! Puns to follow:
    "Electric Light Orchestra"
    "Silence of the LAMB"
    etc ๐Ÿ˜€

  2. Avataaar/Circle Created with python_avatars Emad Abuhagag says:

    thanks

  3. Avataaar/Circle Created with python_avatars richardnanis says:

    The LAMB! That sounds sweet!
    Wouldn't it be much easier just to use a little variable dummy load? You can buy a 60W dummy load from china for about 15 Eur and it would do the job perfectly ๐Ÿ™‚ You can also use some bigger resistors capable of handling the power of the solar panel. Or a power potentionmeter of around 100ohms here would do the job ๐Ÿ™‚
    In my experience when you use the panel just for charging batteries you can use a DC-DC Buckconverter and it will automatically nearly find the MPP if you adjust the buck conveters output voltage a little over battery voltage or even max. end of charge voltage. Others doubt that this will be near the MPP – from a discussion in a photovoltaic forum.

  4. Avataaar/Circle Created with python_avatars Jessica Ryan says:

    What code did you use for this please.

  5. Avataaar/Circle Created with python_avatars imjeff88 says:

    cool LAMB lol i do the some thing only with Christmas lights they make a great dummy load i use two 20 foot stings ย 

  6. Avataaar/Circle Created with python_avatars Raymond Earle says:

    You could change them for leds. LOL. With the equivalent power I would be able to see the glow from here in bright sunlight. LOL LOL. My apologies I forgot they were incandescent. Looking forward to Arduino unit. I bought an UNO. Now learning to program. Yup even at 63 I have a thirst to learn. In fact you could say I am like number 5. "More input" "More input" "more input".

  7. Avataaar/Circle Created with python_avatars Julian Ilett says:

    I couldn't possibly condone the use of 99 incandescent lamps as a bench light! If these experiments result in a working MPPT charge controller, I will make 2 versions: an Arduino version which is open source and a microcontroller version which is proprietary.

    Thanks Raymond for your continued support.

  8. Avataaar/Circle Created with python_avatars Raymond Earle says:

    Well done Julian. So you have a manually adjustable load that could give you a bit of bench light too. Are you doing this system for future production or is the code going to be available? Wouldn't mind having a go. Looking forward to your plotting system. Once again. Well done.

  9. Avataaar/Circle Created with python_avatars Julian Ilett says:

    Finding Maximum Power with the LAMB

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